Piping System
Gas system
- The gas dynamic pressure is 16~35kPa, and static pressure is ≤50kPa, the pressure out of this range can be accommodated by special orders.
- Drain valve should be installed at the lowest part of gas pipes. All connecting pipes must be cleaned and tested for air tightness with 0.6MPa air when gas piping system is completed.
- When two or more units are connected in parallel, a buffer pipe (with diameter 3~6 times of the main pipe) must be installed at the main pipe to avoid flameout due to gas low pressure caused by simultaneous startup. Manual drain valve should be equipped at the bottom of the buffer tube.
- Customers are required to inform BROAD of the fuel type, heating value and pressure so that a burner can be properly selected. BROAD is responsible for installation of gas train valves within supply scope. External gas piping system is to be installed by customers to 1m distance from the burner.
- The ball valve of BROAD gas valve train must be closed if customers need to test piping pressure so that gas train valve will not be damaged by high pressure.
- A gas leakage alarm (acting value must be set 20% lower than danger value lower limit) must be equipped in machine room with a linkage system with draft fans. Machine room must be well ventilated all the time.
Oil system
- Oil system includes oil storage tank, oil pump, daily oil tank, oil filter and metering instruments. Oil tank should be equipped with oil check nozzle, air vent (breather valve), oil refill valve, oil level sensor and drain valve. The lowest oil level of daily oil tank must be 0.1m higher than the burner.
- Oil pipe should be copper pipe or seamless steel pipe and leakage test should be taken at a minimum pressure of 0.8MPa.
- Medium filters are to be installed at inlet and outlet of oil storage tank. The filters should have enough section area, and should be convenient to install/uninstall and drain.
- Oil tank should be equipped with metering device for energy saving management.
Steam system
- The supply of the steam should be pressure-stable. The upper limit should not be over 110% of the rated pressure. If the pressure may exceed the upper limit, a regulating valve should be equipped in the pipeline.
- Safety valve should be fixed in the steam inlet pipeline. The protection value is adjusted as 110~130% of its working pressure. The safety valve should be connected to outdoor to avoid the overpressure of the system.
- Condensed water can be stored in an open tank beside the chiller, and then pump back to the boiler by a condensed water pump or steam trap pressurizer.
- Remove the condensed water from steam thoroughly before steam entering chiller.
Water system
- The initial filling of the chilled/heating water must be soft water. The leakage rate should be less than 10% every year, or else large amount of city water makeup will cause water system scaling.
- Minor leakage in chilled/heating water system is made up from the expansion water tank. An open expansion water tank instead of a closed expander is recommended for pressure balance. The water expansion volume is calculated as 4% of total water volume in the system.
- Chiller, pumpset and cooling tower should be in one to one correspondence to achieve better energy efficiency.
- Regarding to BROAD non-packaged chiller, the heating water and hot water three-way valve is installed in customer’s piping system, and it will be packaged separately and delivered together with chiller.
- Auto dosing system should be installed in cooling water pipe or cooling tower. Auto drain valve (motor valve) should be set at the lowest point of cooling water system (BROAD packaged pumpset included).
- When the distance between cooling tower and machine room is ≤30m, the cooling water pipe diameter can follow the dimension drawing. If it's 30~90m, the pipe diameter shall be enlarged by one size. If it's >90m, the pipe diameter shall be enlarged by two sizes.
- For the water system, zero resistance filter, instead of Y-shape filters, with section area 8~15 times larger than pipe section area shall be used to minimize the water resistance.
- Soft connector must be installed at inlet/outlet of chilled/cooling water system. The weight of the external piping system can never be borne by the chiller.
- The installation site of the cooling tower should be far from heat source, especially should be at least 6m far from the chimney, or the chimney should be 2m higher than the top of the cooling tower.
- The cooling tower and cooling water system should be far from pollution sources like acid or alkali. If there is a pollution source, information should be delivered when ordering.
- Piping requirements: all pipes and valves should not go across the space above the chiller to avoid damage caused by pipe installation, maintenance or leakage.
- Secondary heat exchange hot water system is recommended for areas with very hard water.
- Hot W. system for BY20, BY30, BY50 must adopt secondary heat exchange.
Exhaust system
- It is recommended that independent stack be used for each chiller. If chillers share a common stack, it must be inserted type and the main stack must be bigger and higher. Exhaust motor valve shall be installed for each duct.
- The exhaust volume is dependent on the fuel heat input. It is estimated at 1.55m³ per kW fuel input. 3~5 m/s flue gas flow velocity in the stack is recommended.
- Fouling collector should be installed at flue duct inlet to prevent condensate from flowing into the chiller. The indoor flue duct and high outdoor steel stacks must be insulated. No insulation is required for low outdoor steel stacks.
- Locate the exhaust outlet as far as possible from the cooling tower, or 2m higher. The rated exhaust outlet temperature is 160°C, but insulation materials and fire isolation design should be based on 300°C for safety.
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